Name: Mount Polley mine.
Location: Mount Polley is located in south-central British Columbia, Canada, 56 km north-east of Williams Lake.
Controlling Company: The project is owned and operated by Mount Polley Mining Corporation (MPMC), a subsidiary of Imperial Metals Corporation.
Brief Description: Mount Polley is an openpit copper/gold mine, with an underground component. The property comprises 20 113 ha, consisting of seven mining leases totalling 2 007 ha, and 46 mineral claims encompassing 18 106 ha.
The project has a mine life to 2026.
Brief History: Mount Polley started operating in 1997. Mining continued until September 2001, when operations were suspended, as a result of low metal prices.
In December 2004, Mount Polley reopened with mining in the Wight and Bell pits, with mill production starting again in March 2005. Mining during the next ten years saw the completion of the Wight, Bell, Pond Zone and Southeast pits.
In August 2014, a breach of the tailings storage facility occurred at the Mount Polley mine causing water and tailings to be released. The mill was shut down, and put on care and maintenance.
In August 2015, the mine resumed modified operations and in June 2016 it received authorisations to return to normal operations.
The mining was suspended once again January 2019, owing to poor market conditions.
Products: Copper, gold and silver.
Geology/Mineralisation: The Mount Polley Intrusive Complex (MPIC) hosts the Mount Polley copper/gold porphyry deposit. It is a late Triassic magmatic centre, about 6 km × 4 km, elongate in a north-north-west direction. It comprises alkalic, marginally silica-undersaturated intrusions and magmatic-hydrothermal breccias. The deposit is about 205-million years old, based on uranium/lead isotopic dating; there is close agreement between age determinations from MPIC intrusions and minerals associated with sulphide mineralisation.
Mineralisation occurs in almost all constituent rock types of the MPIC, which indicates that this occurred late in its formation. Nearly all economic mineralisation is in breccias, or in mineralised stockwork veins in adjacent wall rock intrusion. Country rocks of the Nicola Group closest to the MPIC are mafic to intermediate volcanic and subvolcanic coherent rocks, and related breccias, and may form components of mineralised hydrothermal breccias in the periphery of the MPIC.
Reserves: Total proven and probable reserves as at July 2017 were estimated at 73.61-million tonnes grading 0.27% copper, 0.29 g/t gold and 0.56 g/t silver.
Resources: Total measured and indicated resources as at July 2017 were estimated at 247.33-million grading 0.27% copper, 0.26 g/t gold and 0.67 g/t silver. Inferred mineral resources are estimated at 14.03-million tonnes grading 0.16% copper, 0.17 g/t gold and 0.35 g/t silver.
Mining Method: Conventional shovel, truck and openpit mine. With a developing underground mine.
Major Infrastructure and Equipment: Current project infrastructure includes the mill (with a 16 800 t/d capacity) and crusher facilities; active mining in the Cariboo pit and in the Boundary Zone underground operation, with the portal in the bottom of the completed Wight pit. It includes two active rock disposal sites; a south-east rock disposal site; and temporary north-west potentially acid-generating stockpile; access roads; power lines; a tailings storage facility, with a tailings pipeline from the mill; drainage collection systems; and sediment/seepage control ponds.
Prospects: On January 7, 2019, MPMC announced that the Mount Polley mine operations would be suspended as a result of declining copper prices. Milling of low-grade stockpiles are targeted to extend operations until the end of May 2019.
Full operations will resume once the economics of mining at Mount Polley improve.
Contact Details:
Imperial Metals Corporation
Tel +1 604 669 8959
Email inquiries@imperialmetals.com
Website https://www.imperialmetals.com